This Phase I SBIR research effort is to demonstrate feasibility of cushioning yet tougher bioelastic transdermal drug delivery patches for placement over pressure susceptible bony prominences for prevention of pressure ulcers, while more fully accessing the unique capacity of the patches for sustained release of therapeutic drug to the dermis. Previous efforts demonstrated sustained therapeutic release for weeks and remarkable efficacy, but for a 25 to 30 percent incidence of patch breakage under the most severe, medial malleolus, point of shear stress in the dog coaptation (walking) cast model of Swaim. The specific aims of this Phase I proposal are to develop tougher membranes with even better loading and release capacities in preparation for full scale testing during the Phase II: 1) By preparing and testing in vitro three compositions of bioelastic polymers as membranes for improved toughness and near zero order release profiles, 2) By assessing efficacy of the bioelastic patches alone and when loaded with a thromboxane synthetase inhibitor (TSI) for preventing or reducing the severity of pressure induced wounds. This feasibility study utilizes four groups of dogs: Group I (n = 6, controls) with no bioelastic patch placed over the medial malleolus, Group II (n = 6, patches without TSI), Group Ill (n = 6, patches impregnated with 1.0 mg/cm2 of TSI) using one of the two chosen polymers, and Group 4 (n = 6, patches impregnated with 1.0 mg/cm2 of TSI) using the second selected polymer. PROPOSED COMMERCIAL APPLICATION: Treatment of pressure (decubital) ulcers cost $1.6 billion/year in the U.S. Pressure ulcers, once having occurred, greatly facilitate recurrence. Current means of successful prevention is labor intensive and therefore adds further to the health care burden. With a growing geriatric population the present outlook is for mounting costs. An effective, relatively low cost means of prevention is the appropriate solution. Cushioning, tough bioelastic membranes of unique biology-like drug delivery capacity can provide the solution to prevention.